The present invention relates to a single-lens reflex camera provided with a strobe and a distance measuring device for measuring the distance to an object to be photographed based on the principle of triangulation. More particularly, a camera wherein position of a light flashing block, in which the strobe device and a distance measuring device are provided, is changed from an operating position, where a light transmitting element of the distance measuring device and the strobe light flashing unit are directed towards the object and a non-operating position where the light transmitting element and the strobe light flashing unit are faced downwardly.
In general, AF (Automatic Focusing) single-lens reflex cameras are provided with a TTL (Through the Lens) type distance measuring device. More specifically, the distance from the camera to an object to be photographed is measured by the light from the object passing through a taking lens, whether the distance is measured by a phase difference detection system or by a contrast detection system, and then a focusing lens is driven to be moved in accordance with the measured distance. In the single-lens reflex camera, since a focusing operation, for each of the different types of exchangeable lenses, ranging from a wide-angle lens to a tele-photo lens, must be performed in the same manner, it is necessary to perform the distance measuring by means of a TTL type device.
Recently, however, single fixed-lens type reflex cameras have become commercially available, since the performance of zoom lenses has been improved. These fixed-lens type cameras do not always necessitate the use of TTL type distance measuring devices, but can use distance measuring device based on the triangulation principle (a triangulation distance measuring device) widely used in compact cameras. The TTL system is limited in its distance measurement ability depending on the diameter of the aperture of the taking lens. I in particular, when a wide-angle lens is used, the limitations on TTL measurements are severe. On the other hand, triagulation distance measuring devices do not have such limits and thus are preferable. When an active type triangulation distance measuring device, which transmits infrared light for distance measurement, is used in a single-lens reflex camera including a large photographing lens, it is very possible that the distance measuring infrared light is blocked by the taking lens, and in particular there is a problem in that a lower distance measuring zone is blocked by a wide-angle lens. To avoid the occurrence of the above problem, a distance measuring infrared light transmitting unit must be spaced from the taking lens, which results in an increased size for the camera body. Further, a passive type triangulation distance measuring device, i.e., a pair of light receiving elements, each of which receives light from the object and the distance between the camera and the object is measured in accordance with the difference in phases of the received light, has the same problem in that light from the object is blocked by the taking lens in the same manner, when the pair of the light receiving elements are positioned in the vicinity of the taking lens.
Further, recent single-lens reflex cameras are generally of the type containing a strobe device, and when the strobe device has a light flashing unit positioned in the vicinity of a taking lens, a so-called red-eye phenomenon is caused. The problem of the red-eye phenomenon can be solved when the strobe light flashing unit is spaced from a taking lens, and thus various kinds of retractable type strobe devices are used. It is difficult, however, to provide adequate distance between the strobe light flashing unit and the taking lens sufficient to totally prevent the red-eye phenomenon in a conventional arrangement.